Effect of allogenic hematopoietic stem cell transplantation on tumor recurrence and metastasis of hepato-cellular carcinoma after radical hepatectomy

Abstract

Objective To evaluate the effect of alIoHCT on recurrence and metastasis of HCC after hepatic radical resection. Methods Umbilical cord blood were collected after labor. The efficacy of separa-tion by 6% hydroxyethyl starch (6% HES) and NH4CL lysing solution were examined. Twenty-two SCID mice were randomized into the scheduled transplantation group (n=8), the single transplantation group (n =8) and the normal saline group (n=6). Human nucleated cells (NC)at a amount of 5×107 were transfused through the tail vein into the 2 groups of transplantation. All the mice in the 3 groups received cyclophospha-mide (CTX) as conditioning regimen before tansplantation and Methylprednisolone (MP) for 1 week continu-ously after trasplantation. Hematopoietic and immune recovery, graft versus host disease (GVHD), engraft-ment and survival rate were observed after transplantation. Six weeks after alloHST, the orthotopic tumor model in SCID mice was established by implanting histologically intact tissue under the embrane of liver. Ten days later, the mice received radical resection of lobe bearing tumor. The condition of recurrence and metas-tasis was observed 4 weeks after operation. Results A murine model of umbilical cord blood transplantation using CTX and MP as conditioning regimen could be successfully established in SCID mice. The percentage CD34+ cells of peripheral blood NC in scheduled transplantation group and single transplantation group was 1.66%±0.47% and 0.68% + 0.56%, respectively. There was significant statistical significance (P<0.01). The intrahepatic recurrence rate after operation was 100% in all the 3 groups. However, the recur-rent tumor volume was (367.18±31.86) mm3 , (648.26±155.22) mm3, (811.38±127.36) mm3, re-spectively in the 3 groups. There was marked difference among the 3 groups (P<0.01). The inhibitory rate of group A and B was 54.7% and 20.1%. The incidence of lung metastasis was 14.3 (1/7), 6.7% (4/6) and 100% (5/5), respectively in the 3 groups and there was remarkable difference (P<0.01). The inci-dence of celiac lymph node metastasis was 14.3 (1/7), 33.4% (2/6) and 40% (2/5), respectively in the 3groups and there was no significant difference (P=0.58). Conclusion AlloHSCT is a useful method for de-creasing metastasis and recurrence of liver cancer after radical resection in early stage. Key words: Carcinoma hepatocellular; Hematopoietic stem cell transplantation; Neoplasm recurrence; Neoplasm metastasis